Alberta Channel Classification
The plan: examine both data sets
1 Explore the data
We are working with channel survey data from two areas in Alberta, Area C and Spray Lake, shown in the location map below.
We have data from field surveys of channels at each study site. The surveyed channels are classified into five types:
Ephemeral (EPH), little or no channel development
Intermittent (INT), \(\le\) 0.4 meters width for Area C, \(/le\) 0.5 for Spray Lake
Transitional (TRANS), \(\gt\) 0.4 to 0.7 meters for Area C, 0.5 to 1.0 for Spray Lake
Small Permanent (SMPRM), \(\gt\) 0.7 to 5.0 meters for Area C, 1.0 to 5.0 for Spray Lake
Large Permanent (LGPRM), \(\gt\) 5.0 meters for both areas.
We also have lidar-derived DEMs for the two areas, from which synthetic channel networks have been developed. Our goal is find attributes of the basins and their channels inferred from the DEMs that correlate with the surveyed channel type. We can then predict the channel type for channels in the synthetic network that do not have surveys associated with them.
The Area C analysis area covers 5,640 km2 with 59,938 km of modeled synthetic channels and 1,142 km of surveyed reaches. The Spray Lake analysis area covers 2,090 km2 with 10,122 km of modeled synthetic channels and 1,217 km of surveyed reaches. This is a rather dramatic difference in channel density, from 10.6 km/km2 for Area C to 4.8 km/km2 for Spray Lake. I am unsure what actual physical difference in channel density this represents. The initiation points for the synthetic network are pushed further upslope than expected channel-head locations because we want it to extend into the zero-order portion of the network to include surveyed ephemeral channels. Some unknown portion of the total synthetic-network channel length thus extends upslope of physical channels and this portion may differ between the two study sites.